• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.5
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• pp.707-713
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• 2013

Coupling bolts have replaced conventional fitted bolts in applications where the operator's safety during assembly/disassembly is of concern or where the cost of process interruption is significant. Coupling bolts have been installed on rotating flange couplings in a wide range of marine and power applications worldwide. Their use has been approved by all leading international and national classification societies and regulatory bodies. A coupling bolt is a hydraulically tensioned fitted bolt that creates a stable and rigid link between coupling flanges and simplifies assembly and disassembly. We measure the bolt dimensions for reverse engineering and study the standard of assembly-load using a mechanical formula in order to localize a coupling bolt for a shaft in a power plant. We experimentally obtain the friction coefficient and confirm the condition of bolt sets through structure analysis. We show the variation of contact pressure for the shape parameter in order to consider the result when redesigning a bolt.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.1
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• pp.98-103
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• 2001

Machining is the commonly used process in the manufacturing of prototypes. This process offers several advantages, such as rigidity of the machine, precision of the machine, precision of the operation and specially a quick delivery. The weight and immobility of the machine support and immobilize the part during the operation. However, despite these advantages it shows, machining still presents several limitations. The immobilization, location and support of the part are referred to as fixturing or workholding and present the biggest challenge for time efficient machining. So it is important to select and design the appropriate fixturing assembly. This assembly depends on the complexity of the part and the tool paths and may require the construction of dedicated fixtures. With traditional techniques, the range of fixturable shapes is limited and the identification of suitable fixtures in a given setup involves complex reasoning. To solve this limitation and to apply the automation, this paper presents the Reference Free Part Encapsulation(RFPE) and implementation of the encapsulation system. The feature-based modeling system and the encapsulation system are implemented. The small part of which it is difficult to find out the appropriate fixturing assembly is made by this system.

• Korean Journal of Materials Research
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• v.23 no.8
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• pp.453-461
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• 2013

Controlling the stick and slip motions of the contact lines in a confined geometry comprised of a spherical lens with a flat substrate is useful for manufacturing polymer ring patterns. We used a sphere on a flat geometry, by which we could control the interfaces of the solution, vapor and substrate. By this method, hundreds of concentric ring-pattern formations of a linear conjugated polymer, poly [2-methoxy-5-(2-thylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV), were generated with excellent regularity over large areas after complete solvent evaporation. Subsequently, the MEH-PPV ring patterns played a role as a directed template to organize highly regular concentric rings of single-walled carbon nanotubes(SWCNTs); when a droplet of the SWCNT suspension in water was casted onto the prepared substrate, hydrophobic polymer patterns confined the water dispersed SWCNTs in between the hydrophilicized $SiO_2/Si$ substrate. As the solvent evaporated, SWCNT-rings were formed in between MEH-PPV rings with controlled density. Finally, we used a lift-off process to produce SWCNT patterns by the removal of a sacrificial polymer template with organic solvent. We also fabricated a field effect transistor using self-assembled SWCNT networks on a $SiO_2/Si$ substrate.

• Journal of Applied Biological Chemistry
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• v.63 no.3
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• pp.189-195
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• 2020

The soybean (Glycine max L.), also known as the soya bean, is an economically important legume species. Pathogens are always major threats for soybean cultivation. Several pathogens negatively affect soybean production. The soybean is also known as a susceptible host to many viruses. Recently, we carried out systematic analyses to identify viruses infecting soybeans using soybean transcriptome data. Our screening results showed that only few soybean transcriptomes contained virus-associated sequences. In this study, we further carried out bioinformatics analyses using a soybean flower bud transcriptome for virus identification, genome assembly, and single nucleotide variations (SNVs). We assembled the genome of Soybean yellow common mosaic virus (SYCMV) isolate China and revealed two SNVs. Phylogenetic analyses using three viral proteins suggested that SYCMV isolate China is closely related to SYCMV isolates from South Korea. Furthermore, we found that replication and mutation of SYCMV is relatively low, which might be associated with flower bud tissue. The most interesting finding was that SYCMV was not detected in the cytoplasmic male sterility (CMS) line derived from the non-CMS line that was severely infected by SYCMV. In summary, in silico analyses identified SYCMV from the soybean flower bud transcriptome, and a nearly complete genome of SYCMV was successfully assembled. Our results suggest that the low level of virus replication and mutation for SYCMV might be associated with plant tissues. Moreover, we provide the first evidence that male sterility might be used to eliminate viruses in crop plants.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.24 no.2
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• pp.129-150
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• 2013

The libraries of local councils contribute to realize democracy and promote national interests and the welfare of the people, by supporting democratic legislation activities and congressional politics of the local councilors. This study analyzes the libraries of local councils at 17 regional local governments, and it confirms that there are various deviations in their library services such as material acquisitions and legislative information services by regional groups. On the basis of that analysis, the study summarizes the ways for improving the service qualities of the libraries of local councils as follows. First, it is necessary to organize the institute for national council materials. Second, the cooperative network systems should be constructed to share council publications. Third, the provisions related the copyright law and the national assembly library act have to be modified. Fourth, the libraries of local councils share their own materials focusing on digital publications. Fifth, the National Assembly Library expands their legislative information services to the libraries of local councils.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.8
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• pp.489-493
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• 2017

Microbial fuel cells (MFC) are bio-electrochemical processes that can convert various organic materials present in wastewater into electrical energy. For scaling-up and practical application of MFC, it is necessary to investigate the effect of anode size, electrode distance, and total area of anode on substrate degradation. Spaced electrode assembly (SPA) type microbial fuel cell with multiple anodes treating domestic wastewater was used for simulation. According to computer simulation results, the shorter the distance between electrodes than the size of single electrode, the faster the substrate degradation rate. Particularly, when the total area of the anode is large, the substrate decomposition is the fastest. In this study, it was found that the size of the anode and the distance between the electrodes as well as the cathode electrode, which is known as the rate-limiting step in the design of the microbial fuel cell process, are also important factors influencing the substrate degradation rate.

• Korean Chemical Engineering Research
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• v.53 no.6
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• pp.690-694
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• 2015

Recently, direct formic acid fuel cells (DFAFC) among direct liquid fuel cells is studied actively. Economical hydrocarbon membranes alternative to fluorinated membranes for DFAFC's membrane are receiving attention. In this study, characteristics of sulfonated poly(ether ether ketone, sPEEK) and sulfonated poly(arylene ether sulfone, PAES) membranes were compared with Nafion membrane at DFAFC operation condition. Formic acid crossover current density of hydrocarbon membranes were lower than that of Nafion 211 fluorinated membrane. I-V performance of sPEEK MEA(Membrane and Electrode Assembly) was similar to that of Nafion 211 MEA due to similar membrane resistance each other. sPEEK MEA with low formic acid crossover showed higher stability compared with Nafion 211 MEA.

• The Korean Journal of Applied Statistics
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• v.30 no.3
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• pp.403-415
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• 2017

In this paper, we investigate cosponsorship networks found in the 17th National Assembly of Republic of Korea. New legislation should be sponsored by at least 10 legislators including one main sponsor. Cosponsorship networks can be constructed, using directional links from cosponsors of legislation to its main sponsor; subsequently, these networks indicate the social relationships among the legislators. We apply Exponential Random Graph Model (ERGM) for valued networks to capture structural properties and the covariate effects of networks. We find the effect of the same party has the greatest influence on the composition of the network. Mutuality also plays an important role in the cosponsorship network; in addition, the effect of the number of elections won by a legislator has a small but significant influence.

• Journal of the Korean Society for Library and Information Science
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• v.50 no.3
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• pp.513-532
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• 2016

Legal deposit is a system that a person who publishes in the country a work shall deposit a certain copies of publications in designated libraries or institutions in order to preserve and transfer national knowledge and culture heritage. Under "Libraries Act" and "National Assembly Library Act", depositors shall present books to the Library and the Library shall properly compensate him/her for such copies presented. This study focuses on presentation and proper compensation of books. This study has reviewed laws and regulations about them in major countries and our country, and analyzed the current status and some problems of our country. This study has analyzed the constitutionality of legal deposit, the refusal of copies presented, and the meaning of proper compensation through analyzing cases on legal deposit. Based on these analyses, it has proposed the modification of regulations on presentation and proper compensation of books, the establishment of specific rules on proper compensation, and the penalties on unfair presentation.

• Journal of the Korean Chemical Society
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• v.51 no.6
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• pp.526-535
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• 2007

Ru(II)-terpyridine complexes (8, 9, 11) linked with adamantyl or β-cyclodextrin moieties were synthesized and characterized based on their 1H and 13C NMR spectra as well as MS spectra. Ru(II)-terpyridine complexes (8, 11) linked with adamantyl moiety were readily dissolved in aqueous solution via encapsulation by β-cyclodextrin when they were mixed with an equimolar amount of β-cyclodextrin. In the similar way, the adamantane guest of the Ru(II)-terpyridine complexes (8, 11) were encapsulated by β-cyclodextrin moiety of the ruthenium complex 9 to afford supramolecular assemblies in aqueous environment. Formation of assemblies was corroborated by 1H NMR spectroscopy.